Typewriting machine



April 21, 1925. 1,534,116

E. B. HESS TYPEWRITINGMACHINE Filed June 22, 1922 2 Sheets-Sheet l Q Q U Th :12 M

April 21, 1925. 1,534,116 v E. B. HESS TYPEWRITING MACHINE Filed June 22, 1922 2 Sheets-Sheet 2 l |||||II Patented Apr. 21, 1925.

UNITED STATES PATENT OFFICE.

EDWARD B. HESS, 0F MANHATTAN BEACH, NEW YORK, ASSIGNOR TO ROYAL TYPE- WRITER COMPANY, INC., 015 NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TYPEWRITING MACHINE.

Application filed June 22, 1922. Serial No. 570,176.

To all whom it may concern:

Be it known that I, EDWARD'B. Hnss, a citizen of the United States, residing at- Manhattan Beach, in the county of Kings, New York, and State of New York, have invented certain new and useful Improvements in Typewriting Machines, of which the following is a specification.

In my Unlted States Patent No. 1,390,708 of Sept. 13, 1921, I have shown a typewriting machine in which the type action is such that the noise produced by the impact of the type bars on the platen is materially reduced owing to the fact that the type bars are moved by the full depression of the key levers only to a point a considerable distance from the platen, the further movement of the type bars to the platen being caused by their momentum, this latter part of the movement of the type bars being resisted to some extent by the fingers of the operator.

The machine shown in said patent was equipped with the usual soft cylindrical platen in order to assist in the reduction of noise. It was found in practice that owing to the reduction in force with which the type bars struck the platen and to the fact that the platen was soft and yielding, a large number of good carbon copies could not be obtained although a few good copies, such as are generally desired, could be readily produced. It is the principal object of my present invention to provide means whereby a machine, equipped with a soft noise reducing cylindrical platen for. producing a few copies for general service and with a noise reducing type action, may be also' provided with means whereby a large number of good carbon copies may be obtained.

In carrying out my invention I add to the machine constructed as shown in my before mentioned patent of Sept. 18, 1921, an auxiliary platen in the form of a strip preferably of metal which may be readily placed in active position in the line of print so as to receive the impact of the type bars and may as readily be withdrawn from active position when multiple manifolding is not desired.

There are various ways in which this dosirable result may be obtained, some of which are shown'in my applications for Patents 1 0. 555,853, filed April 21, 1922,

and No. 568,171, filed June 14, 1922. My original invention contemplated the use of a metal strip supported in the carriage frame in front of the mainor cylindrical platen and provided with means for moving it from inactive to active position and vice versa, and this specific form of the invention is herein shown and claimed and claims are also herein made to the broad or generic features of the invention to which the devices shown in the applications for patents above mentioned are subordinate. It will, therefore, be understood that while only one specific form of the invention is herein shown, said invention is believed to be a generic one and is so claimed.

\Vhen an auxiliary platen of hard mate rial is interposed between the type bars and a soft cylindrical platen of usual construction, the return movement or rebound of the type bars is changed, the speed of the return being materially reduced and in order to correct this difference, I have provided a main or cylindrical platen of special construction, i. e., one having within it a yielding zone or layer which adds to the elasticity of the platen as a whole while not rendering too soft the striking surface thereof. Such a platen is not only serviceable for general use when a few copies are desired and when the auxiliary platen is not in service, but also when the auxiliary platen is in active position for obtaining a large number of good carbon copies. In either case the return movement or rebound of the type bars is quick and substantially uniform.

The accompanying drawings show one efficient way of embodying my invention in a front strike visible machine but as before stated other ways of carrying out the invention are contemplated.

Figure l is a view in side elevation. of portions of a typewriting machine showing how my improvements are applied thereto. It will be observed that the type action is similar to that shown in my before mentioned patent.

Figure 2 is a view of the machine looking at the inside of the left hand side plate of the carriage, the auxiliary platen being in inactive position and a type bar at the printing point.

Figure 8 is a detail view looking at the outside of the right hand side plate of the carriage and showin the devices for moving the auxiliary p aten into and out of active position. In this figure of the drawings, a type bar is shown by dottedlines at a point considerably in advance of the platen, i. e., at the commencement of the momentum period of the type bar and the auxiliary platen is shown in active position.

Figure 4 shows a transverse section of the new form of main or cylindrical platen employed and it also shows the auxiliary platen and some of the devices employed for operating it.

Figure 5 is a front view of the main' or cylindrical platen, the auxiliary platen and its supporting and operating devices. Some of the parts are shown in elevation and some in section or broken away.

Figure 6 is a detail view of one of the links with which the auxiliary platen is connected.

' Figure 7 is another view of the same link.

These Figures 6 and 7 indicate the manner in which the links are connected to the auxiliary platen.

Figure 8 is a view on an enlarged. scale showing the auxiliary platen in cross-section and indicating how it conforms to the curvature of the main platen when in active position.

Figure 9 is a front view of the auxiliary platen detached from its supports showing the'enlargements at its opposite ends and indicating how the links shown in Figures 6 and 7 are connected with it.

Such partsof a typewriting machine as are necessary to illustrate an embodiment of my invention are shown in Figure 1. The main or cylindrical platen is indicated at'A. B indicates a part of the right hand side plate of the carriageand B a part of the left hand side of the carriage. (l indicates a type bar segment. D a type bar. and E a type bar guide. universal bar is shown at F. The type bars are formed with heels (Z and they are pivotally mounted in the segment as indicated at .(Z. The type bars extend forwardly from their pivots as usual, their front or type carrying ends being normally supported on a cushioned type bar rest G. The heels of the type bars are connected by links H with the universal bar F and the return springs I of the type bars are connected to the rear portions of the heels of the type bars and to a rear support J. The key levers L are pivotally mounted at their rear ends in a support M and these levers are normally pulled against a cushioned stop N by light springs N. No stops are employed to arrest the downward movement of the key levers. this downward movement being cushioned in a manner hereinafter explained.

The front links 0 are pivotally connected at o with a support P as heretofore and each front link is connected by a rod or pull link Q with the heel of a type bar. Each link 0 is connected with a key lever by a link R in the usual way.

It will be observed that the rear end of the link Q is connected with the heel of th type bar at a point below the type bar pivot and approximately in the same vertical plane as its pivot. The connection is such that when a key lever is depressed to its fullextent, the type bar is moved not all the way to the platen but to a point in vfront of the platen and at a considerable distance therefrom as shown in Figure 3, the further movement of the type bar to the platen being caused by its momentum. This construction and operation is more fully described in my Patent No. 1,390,708 of Sept. 13, 1921, before mentioned. In Figure the position of the type bar at the commencement of the momentum period is indicated by dotted lines as is also the position of the pull link Q and at this time the point m where the link Q is pivotally connected with the heel of the type bar is in a straight line passing through the type bar pivot and the point y where the link Q, is pivotally connected'with the front link 0. This is what is termed in my prior patent a toggle looking or dead center position and this position is assumed by the parts referred to when a key lever is depressed to its full extent. but owing to the momentum of the type bar it is carried to the printing point and the toggle lock is broken. When the toggle lock is thus broken, the key lever tends to rise from its depressed position but its movement is resisted by the finger of the operator and thus the force of the im actof the type bar on the platen is reduce A type action of the kind just described and as more fully described in my prior patent reduces materially the noise produced by the impact of the type bars on the platen and in order t-o'assist in the reduction of noise it has been my custom. to employ a soft cylindrical platen of the kind ordinarily used for general service. When the machine is equipped in this way. a few good carbon copies can be obtained. but it has been found that owing to the reduction of the force of the impact of the type bars on the platen. it is not possible to obtain a large number of good carbon copies as is often required. Obviously this difficulty could be overcome by substituting a hard cylindrical platen for the soft one each time that a change from ordinary l'nanifolding to multiple manifolding is desired. but such an expedient is not always practical as ordinarily the operator is not snliiciently skilled to make the change. It is. therefore. desirable that some means he provided for presenting in a simple way a hard surface to the type bars whenever multiple mani folding is desired, and it is desirable that this hard surface should be associated with the main or soft platen in such a way as to not interfere with its usual operation in feeding paper and in order that the main platen may serve as a backing or reinforce for the auxiliary platen. During many experiments and tests in the development of this invention I have provided several ways of accomplishing the desired result. The specific form of the invention shown in the drawings has been thoroughly tested and is very efficient.

The auxiliary platen shown is in the form of a strip of metal S of a length to extend from end to end of the main platen longitudinally and sufficiently wide to cover the line of print. It is curved to conform with the curvature of the main platen and it is of the same thickness throughout. It may be conveniently made of sheet metal bent to the desired form and it has a smooth surface at front and rear. At each end it is enlarged or widened as shown in Figure 9 to provide a more extended bearing or guiding surface and it is formed with T shaped arms 8 to connect it with its operating mechanism.

The flat straight end parts of the auxiliary platen extend through straight vertical slots 6 formed in the side plates of the carriage. These slots are tangential to the curved front surface of the main platen as clearly shown in the drawings. The end parts of the auxiliary platen are arranged slightly in front of that part of the auxiliary platen which covers the line of print. This is shown most clearly in Figure 8 where it will be observed the slots 6 are a short distance in advance of the main platen while the curved part of the auxiliary platen lies close to the surface of the main platen. By this arrangement the main platen provides a firm backing for the auxiliary platen when the latter is in service. The slots 1) are of such length that the auxiliary platen may be moved and guided from one position to another and may be arrested at the end of each movement so as to prevent possibility of overthrow. In Figures 1. 2 and 4 the auxiliary platen is shown in inactive position while in Figures 3, 5 and 8 it is shown in active position.

Various devices may be employed for locking the auxiliary platen in its different positions and for moving it from one position to another. As shown, the rock shaft a, mounted to turn in bearings in the side plates of the carriage below the main platen, is connected by arms 0 to links 9 which are in turn connected to the arms 8 extending from the opposite ends of the auxiliary platen outside the side plates B, B. An operating lever h is secured to one end of the rock shaft and extends upwardly and rearwardly therefrom close to one of the side plates of the carriage and it is conveniently formed with a finger piece it. The lever I: is preferably formed in one piece with one of the arms 0, and the part c is formed with notches c to receive the toothed end of a pawl m pivoted to the side plate B and pulled toward the notches by a spring m. The construction is such that the auxiliary platen may be moved from one position to another and locked in either position by the pawl. The length of the slots bis such as to limit the movement of the auxiliary platen in either direction and to prevent overthrow and the pawl serves to prevent any possibility of the auxiliary platen being moved from its adjusted position by accident. Obviously the locking devices may be otherwise constructed or located. I have shown only one of the devices which I have used for such purpose and which is best suited to the particular construction of auxiliary platen and an operative mechanism herein shown.

The auxiliary platen and associated parts may be very easily applied to a typewritin machine of usual construction. The slots 2 may be formed in the carriage side plate, or in extensions thereof the ends of the platen may be inserted in the slots 1) and the links 9 may be applied-to the arms 8 in the manner indicated. It will be observed that the upper ends of the links 9 have circular openings 9 formed with offset recesses 9 'When a link is aplied to the auxiliary platen it is held horizontally (Figure 6) and slipped over the T-shaped arm 8 of the platen. The link 9 is then turned downward in the manner indicated in Figure 7 and when in this position the link is prevented from slipping off from the end of the platen. This is a simple but efficient wa of assembling these parts. When the lin {S are thus applied to the auxiliary platen their lower ends may be connected in the manner indicated to the front ends of the arms 0. \Vhen the parts are thus assembled. the auxiliary platen may be held in either position and may be held in inactive position as long as multiple manifolding is not desired, but when many copies are required, by a simple movement of the operating lever the auxiliary platen may be moved into the line of print in front of the main platen in the manner shown in Figure 8:

Inasmuch as the curved auxiliary platen is made of thin sheet metal it has sufficient resiliency to bend to a slight extent and thus its upper edge may readily pass the front of the main platen while rising, but as soon as the auxiliary platen has reached active position, it springs rearwardly into contact with the main platen as shown most clearly in Figure 8. While actual contact between the auxiliary platen and the main platen is desirable, the pressure of the auxiliary platen on the main platen is not such as to interfere with the independent rotary movement of the platen for feeding the paper or for other purposes. When no longer required for multiple manifolding, the auxiliary platen may be quickly lowered to inactive position by a simple movement of the operating lever.

While a soft platen of usual construction may be used for general service and also when associated with an auxiliary platen of the kind shown, I have found that superior results are obtained if the main platen be provided with cushioning and sound muffiing means. When a hard main platen is used, the rebound of the type is reduced and this is also true when'a hard auxiliary platen is used in connection with a soft cylindrical platen of usual construction. I

have overcome this difficulty by providing a soft cushioning means preferably of the kind shown in Figure 4 where U indicates the platen shaft, u a tube or cylinder surrounding the shaft and preferably made of wood, it indicates the space between the wooden tube and the platen shaft, and 14 indicates a soft rubber outer layer of proper consistency to receive the impactof the type. This layer may be made of the rubber compound or of material usually employed in typewriter platens. V indicates an interior layer of soft yielding material, such as rubber, which is softer and more yielding than the outer layer 14 In this way when the auxiliary platen is in active position, not only is the noise somewhat reduced by the special construction of the main platen but the uniform rebound of the type is increased, there being no material difference in this re spect when the auxiliary platen is in use or is withdrawn. I, therefore, prefer to use a main platen of the kind just described in connection with the auxiliary platen and the noise reducing type action although the use of such a main platen is not absolutely essential.

I claim as my invention:

1. In a typewriting machine, the combination with a main cylindrical platen, of an auxiliary platen of relatively hard material, means for moving said auxiliary platen from active to inactive position in the line of print, and means for causing this movement to be tangential to the main platen.

2. In a typewriting machine, the combination with a main cylindrical platen, of an auxiliary platen of relatively hard material, means for moving said auxiliary platen vertically from active to inactiveposition, and means for guiding the auxiliary platen'in a path tangential to the main platen during this movement.

3. In a typewriting machine, the combination with a main cylindrical platen, of an auxiliary platen, means for moving said auxiliary platen to and from active position, and guiding means including slots for the ends thereof which cause this movement to be tangential to the main platen.

4. In a typewriting machine, the combination with a main cylindrical platen, of an auxiliary platen movable to and from inactive position, guiding means which cause this movement to be tangential to the main platen, and means for detaining the auxiliary platen in either position.

5. In a typewriting machine, the combination with a main platen, of an auxiliar platen movable from inactive to active position in the line of print havinga smooth curved portion co-extensive in length with the line of print, and enlarged guiding portions at its ends, and means for supporting and guiding the enlarged ends of the auxiliary platen, in a plane tangential to the main platen.

6. In a typewriting machine, the combination with a main cylindrical platen, of an auxiliary platen movable from inactive to active position in the line of print' and coextensive in length with the line of print and having enlarged guiding portions at its ends moving in straight slotted guides in the frame of the machine.

7 In a typewriting machine, the combination with a main cylindrical platen, of an auxiliary platen having a smooth curved portion co-extensive in length with the line of print and having means at its ends for guiding it from active to inactive position in a plane tangential to the main platen, and devices. for adjusting the auxiliary platen and for holding it in active position.

8. In a typewriting machine, the combination with a carriage frame havin guideslots formed in it, of a main cylindrical platen, an auxiliary platen having a curved portion co-extensive in length with the line of print and having enlarged portions at its ends guided in the slots of the frame, a rock shaft, connections between the rock shaft and theauxiliary platen, and means for turning the rock shaft to move the auxiliary platen from one position to another.

9. In a typewriting machine, the combination with the carriage frame formed with guide slots, of an auxiliary platen having end portions movable in said guide slots and having T-shaped arms projectin laterall from them, a rock shaft, forwar ly extenrf ing arms mounted on the rock shaft, and links for connecting said arms with the auxiliary platen having circular openin formed with offset recesses through Whi the T-shaped arms extend.

In testimony whereof, I have hereunto subscribed my name.

' EDWARD B. HESS. 

